Chemistry Reference
In-Depth Information
Table 8.2
(Continued )
Abbreviation
Oligosaccharide
9
Lacto-N-
neooctaose
Gal(
β
1-3)GlcNAc(
β
1-3)Gal(
β
1-4)GlcNAc(
β
1-6)
Gal(
β
1-4)Glc
Gal(
β
1-4)GlcNAc(
β
1-3)
10
Iso-Lacto-N-
octaose
Gal(
β
1-3)GlcNAc(
β
1-3)Gal(
β
1-4)GlcNAc(
β
1-6)
Gal(
β
1-4)Glc
Gal(
β
1-3)GlcNAc(
β
1-3)
11
para-Lacto-N-
octaose
Gal(
1-3)GlcNAc(
1-3)Gal(
1-4)GlcNAc(
1-3)Gal(
1-
4)GlcNAc(
1-3)Gal(
1-4)Glc
12
Lacto-N-decaose
Gal(
β
1-4)GlcNAc(
β
1-6)
Gal(
β
1-4)GlcNAc(
β
1-6)
Gal(
β
1-3)GlcNAc(
β
1-3)
Gal(
β
1-4)Glc
Gal(
β
1-3)GlcNAc(
β
1-3)
The main structural features of human milk oligosaccharides are the
presence of oligosaccharides containing the type I unit (Gal(
1-3)GlcNAc),
as well as those containing the type II unit (Gal(
1-4)GlcNAc), and that
oligosaccharides containing the type I predominate over those containing the
type II unit. The milk oligosaccharides of other species investigated to date
mostly have the type II but not the type I unit. The many varieties of
oligosaccharides in human milk and colostrum are produced by the addition
of Neu5Ac and/or Fuc residues to these two units.
Isolation of the milk oligosaccharides has more recently been accom-
plished by normal-phase or reverse-phase high-performance liquid chroma-
tography (HPLC) or by high pH anion exchange chromatography with
pulsed amperometric detection (HPEAC-PAD). It is noteworthy, for exam-
ple, that Gronberg et al. (1989, 1990, 1992) isolated several novel minor
oligosaccharides by HPLC using triethylamine as an ion-pair reagent. On
the other hand, the selective separation of specific epitopes has been carried
out by affinity chromatography using a monoclonal antibody or lectin. For
example, Kitagawa et al. (1988, 1989, 1990, 1991a,b, 1993) selectively sepa-
rated oligosaccharides containing sialyl Le
a
, a tumor-related carbohydrate
epitope, by affinity column chromatography in which MSW113, the mono-
clonal antibody specific for this unit, was bound to Protein A-Sepharose
GL4B as a ligand: the oligosaccharides containing sialyl Le
a
were adsorbed
by the column and were then eluted by raising the pH of the eluent.
